CH 17 – WBC Morphology

Five Types of Leukocytes (WBCs)

Granular Leukocytes Eosinophil Neutrophil Basophil

Neutrophil 60-70% of all WBC’s Anatomy Physiology 10-12 µm diameter 2-6 nuclear lobes Fine, pale inconspicuous granules Physiology Respond first to bacteria damage by chemotaxis Phagocytosis After engulfing pathogen releases several chemicals lysozyme strong oxidants defensins

Eosinophil 2-4% of all WBC’s Anatomy 10-12 µm diameter 2 connected nuclear lobes red/orange large, uniform granules, do not obscure the nucleus Physiology exit capillaries, enter tissue fluid combat parasites histamine phagocytize antigen-antibody complexes

Basophil 0.5-1% of all WBC’s Anatomy Physiology 8-10 µm diameter bilobed or irregular nucleus round, blue-black granules may obscure the nucleus Physiology exit capillaries to enter tissue fluid mature into mast cells release heparin, histamine, serotonin – stimulate inflammation Hypersensitivity (allergic) reactions

Agranular Leukocytes Lymphocyte Monocyte

Lymphocytes 20-25% of all WBC’s Anatomy 7-15µm nucleus large and dark stained, round or indented cytoplasm forms a pale blue rim around the nucleus

Monocytes 3-8% of all WBC’s Anatomy Physiology 14-19 µm indented or kidney-shaped nucleus (not round) cytoplasm foamy Physiology slower to arrive but survive longer enlarge, differentiate into fixed and wandering macrophages remove microbes, cellular debris, following injury

End WBC Morphology CH 17